The recall comes as the top automotive safety regulator in the U.S. has warned AV companies about their vehicles interfering with first responders.

Zoox has issued a software recall after one of its robotaxis struggled to navigate a smoke-filled emergency fire scene in June. The Amazon-owned company said Friday that it has shipped to its fleet of 105 vehicles a software update that should address the issue. Zoox told TechCrunch in a statement that the software update “enhances the existing capability of detecting active [emergency] scenes by adding the ability to detect and respond to heavy smoke in certain situations.” Nobody was on board the vehicle during the June incident, and Zoox told the National Highway Traffic Safety Administration (NHTSA) that it is not aware of injuries associated with the problem. The NHTSA’s report doesn’t state where the June incident took place, and Zoox declined to say. Zoox’s recall comes just a week after NHTSA administrator Jonathan Morrison sent a letter to self-driving car companies warning them to stop interfering with first responders. “Let me be clear: the inability to detect and appropriately respond to such situations represents a functional insufficiency,” he wrote. “Emergency scenes are not rare or extreme ‘edge cases.’ As such, NHTSA is today issuing a call to action for AV developers and operators to immediately focus their resources on fixing this issue.” TechCrunch previously reported on how Waymo has had repeated run-ins with first responders as it expands into new cities. The company had at least six incidents as of March of this year in which first responders had to physically move robotaxis from an emergency scene. NHTSA said in its report describing the recall that, on June 20, a Zoox robotaxi “encountered heavy smoke that obscured an active emergency fire scene that was not cordoned off with cones.” The Zoox vehicle “braked hard while attempting to steer away before coming to a stop.” A Zoox teleoperator was able to reverse the vehicle away from the scene, allowing first responders to place traffic cones. Zoox told NHTSA that it conducted an investigation to determine the root cause and identify any similar incidents. The company said “this is the only event of this kind that Zoox has experienced,” and that through late June and early July, it had multiple conversations with the safety regulator about the “severity, frequency, and root causes.” Zoox decided to issue the recall on July 7, one day before Morrison’ letter.